4 replies to this topic

[noons]

So I've finally switched over to a NUC after using the ASIAIR Pro for over 2 years and while I'm enjoying the myriad of tools available (currently running NINA, Stellarium, SharpCap, PHD2), there is a fairly steep learning curve associated with the transition. While I do enjoy a cognitive challenge, I don't really like running into a wall over and over again and my wife would prefer if I didn't spend ALL of my free time troubleshooting software/settings/configurations... ok, to the question:

I'm working through comparing using a flats panel with NINA Flat Wizard against shooting sky flats. While I am struggling with sky flat/dynamic exposure settings which consistently work, my larger question is whether it is possible to rotate my filter wheel to a dark-slide to take the dark flats. I get a dialog to cover my scope in order to take the dark flats, but the rest of NINA interface is locked out at that time and I cannot access the filter wheel to rotate to my dark slide, which covers the sensor more fully than a cap... I'm on a 10" newtonian and there are light leaks around the base of the primary which corrupt my dark flats.

 

Has anyone figured out how to do this? or am I stuck with manually adding the cap and hoping it is dark enough... it never is.

Thanks

 

edit: So far my workaround has been to let the Flat Wizard finish... cancel at the dark flats... go to my flat files and write down all the various exposures to set up a custom sequence to shoot with a dark filter at those exposures and run.... THEN go into a FITS editor script and change the filter type for each subset of DARKFLATS to the appropriate filter...it is a bit tedious to say the least.

Edited by noons, 26 March 2023 - 09:19 AM.

[gsaramet]

Well, it's not how I do it. 

 

First, I keep the flat wizard in... dynamic exposure mode? I think that's what it's called. So all flats are the same exposure. No matter if sky or panel. It's just the way I do it

 

Since all flats are the same exposure, next step is obvious: long live the dark flats library

Now, I got even lazier  - with the agreement of the camera. I switched from dark flats to bias. It works good, and the library is even easier to manage.

 

I used to take the dark flats same as darks - camera off the scope, cap on, all light-leaky areas covered properly.

 

So, my recommendation would be to prevent by using libraries and consistent exposure times for flats - or by using bias if your camera allows it.

[jonnybravo0311]

With a panel where you can control the brightness, you can setup custom sequences and make it so your flats are all the same exposure length. Look at the "Flat Device" section in the advanced sequencer. Setup your sequence something like:

 

Toggle Light On

Switch filter to R

Set brightness to 80

Take 50 flat exposures at 5 seconds

Switch filter to G

Set brightness to 30

Take 50 flat exposures at 5 seconds

...

Switch filter to Black

Toggle light Off

Take 50 dark flat exposures at 5 seconds.

 

Requires you to do a bit of prep work (i.e. figuring out beforehand what brightness value you need to set per filter).

[noons]

Thank you. My dark library has been slowly growing with each iteration of flats, so that will be the eventual solution it seems. I have the 294MM pro and sometimes bias works... and sometimes they don't... I did mask off the back of my OTA so it is nice and dark back there and I tried running my fan all night along with a dew shield and I got my first condensation-free evening in a few weeks.

Thank you both for your replies.

[gsaramet]

I understand that the 294 kinda forces you to use dark flats. I don't know what flat panel system you use, I got my panel powered through a 5$ PWM which allows me to tune the illumination. I aimed for the same 3 seconds exposure, and it worked, even if with a bit of trial and error. A nice library of dark flats worked perfectly... until I went narrowband and got bored with tweaking

 

My dew experience is that the dew shield does wonders. I don't run the fan while imaging - scared of dust and vibrations